You charge this Bluetooth speaker via the covered micro USB charging port. And to get the quickest UE Megaboom 3 charge time, use a medium to high current USB adapter. Also, exercise the battery, and do not leave the speaker on the charger once it has fully recharged.
UE Megaboom 3 Speaker Charge Time: How Long to Reach Full Charge
According to the specs the time it takes to charge this speaker is roughly three (3) hours.
How Long it Plays on a Full Charge
On a complete charge, the UE Megaboom 3 can play for up to twenty (20) hours. But when you play it loudly, especially with extra bass, you will see somewhat shorter lasting power. We’ve seen this Bluetooth speaker run dead in around fourteen (14) hours when played at louder volumes. So to get the longest charge time from it, power saving helps a lot. Just play it only as loudly as you must to hear it well throughout your listening space. Then you will get longer play times.
The Charge Time Gets Smaller as the Megaboom 3 Ages
If your speaker is several years old, then the play time per charge may be less. This is normal for devices with ion lithium batteries like this one.
But by working the battery every now and then, you can slow this charge fall off.
To exercise the battery, run it dead and charge it again every three to six months when not in use.
Also, we suggest that you not leave the speaker plugged into a charger once it has reached full charge. Right after the charging lamps go out, disconnect the speaker as soon as you can. Doing so avoids overcharging it and thus, degrading the battery prematurely.